#include <stdio.h>

void euclid( int a, int b, int *d, int *x, int *y ) {
    int x0, y0;
    if ( b == 0 ) {
        *d = a;
        *x = 1;
        *y = 0;
    } else {
        euclid( b, a % b, d, &x0, &y0 );
        *x = y0;
        *y = x0 - ( a / b ) * y0;
    }
}

int main()
{
    FILE *fin, *fout;
    fin = fopen( "inversmodular.in", "r" );
    fout = fopen( "inversmodular.out", "w" );
    int n, a, x, y, d;
    fscanf( fin, "%d%d", &a, &n );
    euclid( a, n, &d, &x, &y );
    if ( x <= 0 ) {
        x = -(x % n);
    }
    fprintf( fout, "%d", x );
    return 0;
}